The present invention relates to an improved display control apparatus for use with an audio amplifier or other type of amplifier to visually display a gain setting value, such as a sound volume setting level, in one of predetermined color hues.
In recent years, more and more sound amplifiers, such as audio amplifiers, adjust a sound volume setting level through voltage control using an electronic volume control unit. Having no mechanical sliding element, the electronic volume control unit does not substantially deteriorate in performance due to aging and wear and is easy to control remotely.
For example, the electronic volume control unit employs, as a setting operator, a rotary encoder outputting a rotating amount and rotating direction. Thus, a current sound volume setting level can be known from a rotating angle alone. Similarly, in a case where up and down buttons are employed as setting operators, the current sound volume setting level can not be known from the number of button depressions alone. Therefore, it has heretofore been impossible to know or ascertain the current sound volume setting level, except by viewing a display showing a numeral value indicative of the current sound volume setting level or actually listening to a sound generated in accordance with the current sound volume setting level.
For example, the electronic volume control unit retains a sound volume setting level when the power to the audio amplifier was turned off last, so as to retrieve the thus-retained sound volume setting level once the power to the audio amplifier is turned on afterwards. However, while some users may turn off the power after reducing the sound volume setting level to a minimum, other users turn off the power leaving the sound volume setting level as has been used so far to produce a sound with a relatively great volume; such a difference between the users perhaps depends on users"" habits. Therefore, unless the current sound volume setting level is known prior to audible reproduction of tone signals following turning-on of the power, the reproduction of the tone signals is likely to start with an undesirable great volume.
In some cases, an attenuation amount is displayed in a numerical value via LEDs (light emitting diodes), fluorescent display tube, LCD (Liquid Crystal Display) or the like, to show the current sound volume setting level. In such cases, the displayed attenuation amount tends to be difficult to recognize if the display is a little away from the user, due to a small displaying area of the display.
The mechanical volume control unit, in contrast, can indicate the current sound volume setting level by a rotating angle of a small marker provided on a volume setting knob; however, the small marker is difficult to recognize at a distance, and a numerical value indication on the operation panel is also difficult to accurately read.
In view of the foregoing, it is an object of the present invention to provide an improved display control apparatus for displaying a gain setting value in a predetermined hue which allows a user to accurately identify, at a glance, a gain setting value, such as a sound volume setting level, by a displaying hue of a hue-variable display device and which allows the user to set a desired range of gain setting values for changing the displaying hue of the hue-variable display device.
To accomplish the above-mentioned object, the present invention provides an improved display control apparatus for displaying a gain setting value in a color hue, which comprises: an input-upper-limit setting section that sets a predetermined upper limit value of gain setting values to be input to the display control apparatus; and a displaying-hue control section that receives a gain setting value from a variable gain control device. When the received gain setting value is not greater than the predetermined upper limit value, the displaying-hue control section outputs a hue control signal to vary a displaying hue of a hue-variable display device between a predetermined first hue and a predetermined second hue in accordance with magnitude or intensity of the received gain setting value. But, when the received gain setting value is greater than the predetermined upper limit value, the displaying-hue control section outputs a hue control signal to set the displaying hue of the hue-variable display device to the predetermined second hue.
With such arrangements of the present invention, the user can set a desired upper limit of the input gain-setting values that are to be used to change the displaying hue of the hue-variable display device between the predetermined first hue and the predetermined second hue.
In actual use, the variable-gain control device is often operated within a range of gain setting values smaller than its predetermined maximum gain setting value; such gain setting values smaller than the predetermined maximum gain setting value will hereinafter be referred to as xe2x80x9cnormally-used gain setting valuesxe2x80x9d. Even in such cases, by using the input-upper-limit setting section to set, as the above-mentioned predetermined upper limit value, an upper limit of the normally-used gain setting values (hereinafter called a xe2x80x9cpractical upper limitxe2x80x9d), the user is allowed to readily know, at a glance, a varying range of the current gain setting value up to the thus-set practical upper limit by just viewing the displaying hue of the hue-variable display device changing between the first and second hues.
Further, as the current gain setting value is increased, the user can readily recognize arrival at the practical upper limit by the displaying hue of the hue-variable display device changing to the predetermined second hue.
For example, the above-mentioned input-upper-limit setting section may be arranged to, upon detecting activation of an input-upper-limit setting operator, take in a current gain setting value of the variable-gain control device and retain the taken-in value as the predetermined upper limit. This way, the input-upper-limit setting section can be implemented in a simple manner.
According to another aspect of the present invention, there is provided a display control apparatus for displaying a gain setting value in a color hue, which comprises: an input-range setting section that sets a predetermined lower limit value and predetermined upper limit value of gain setting values that are input to the display control apparatus; and a displaying-hue control section that receives a gain setting value from a variable gain control device. When the received gain setting value is equivalent to or greater than the predetermined lower limit value but equivalent to or smaller than the predetermined upper limit value, the displaying-hue control section outputs a hue control signal to vary a displaying hue of a hue-variable display device between a predetermined first hue and a predetermined second hue in accordance with intensity of the received gain setting value. Further, when the received gain setting value is smaller than the predetermined lower limit value, the displaying-hue control section outputs a hue control signal to set the displaying hue of the hue-variable display device to the predetermined first hue. Furthermore, when the received gain setting value is greater than the predetermined upper limit value, the displaying-hue control section outputs a hue control signal to set the displaying hue of the hue-variable display device to the predetermined second hue.
With such arrangements of the present invention, the user can set desired upper and lower limits of the input gain setting values that are to be used to change the displaying hue of the hue-variable display device between the predetermined first hue and the predetermined second hue.
By using the input-upper-limit setting section to set, as the above-mentioned predetermined upper and lower limits, practical upper and lower limits of normally-used gain setting values, the user is allowed to readily know a varying range of the current gain setting value from the thus-set practical lower limit to the set practical upper limit by just taking a glance at the displaying hue of the hue-variable display device changing between the first and second hues.
Further, as the current gain setting value is decreased, the user can recognize arrival at the practical lower limit by the displaying hue of the hue-variable display device changing to the predetermined first hue. Similarly, as the current gain setting value is increased, the user can recognize arrival at the practical upper limit by the displaying hue of the hue-variable display device changing to the predetermined second hue.
For example, the above-mentioned input-range setting section may be arranged in such a manner that, upon detecting activation of an input-lower-limit setting operator, it takes in a current gain setting value of the variable-gain control device and retain the taken-in value as the predetermined lower limit, and that, upon detecting activation of an input-upper-limit setting operator, it takes in a current gain setting value of the variable-gain control device and retain the taken-in value as the predetermined upper limit. This way, the input-range setting section can be implemented in a simple manner.
In one embodiment of the present invention, the predetermined first hue is xe2x80x9cpurplexe2x80x9d or xe2x80x9cbluexe2x80x9d and the predetermined second hue is xe2x80x9credxe2x80x9d. Because such first and second hues can provide displaying hue variations agreeing with human feelings about safety and danger (as in the case of traffic lights), the user can intuitively recognize the current gain setting value. In particular, if the predetermined first hue is set to xe2x80x9cpurplexe2x80x9d, it is possible to make the best of the hue displaying capability of the hue-variable display device.
The following will describe embodiments of the present invention, but it should be appreciated that the present invention is not limited to the described embodiments and various modifications of the invention are possible without departing from the basic principles of the invention. The scope of the present invention is therefore to be determined solely by the appended claims.